Rhyming plays an important role in the study of Chinese phonology. Traditionally it is believed that there are two types of rhyming between finals: free rhyming and mixed rhyming. Finals which rhyme with each other freely constitute a rhyme group, while the rhyming between finals from different rhyme groups can only be mixed rhyming. By analyzing the rhyming in the modern Beijing dialect using a statistical method, we find a third type: semi-free rhyming, which is close to free rhyming. As a whole, these two types can be called pan-free rhyming. Thus, the definition of rhyme group must be revised as the maximum unit of pan-free rhyming, because free rhyming is no longer a transitive relation, i.e., when both final pairs A–B and B–C are free rhyming, A–C may be semi-free rhyming. As for the Beijing dialect, our statistical test results approve that non-érhuà finals are divided into 15 rhyme groups, and subsequent phonological analyses show that words in the same rhyme group share the same nucleus and coda. Besides finals, tones also function apparently in rhyming, but in a different way from the three types mentioned above. As more Chinese dialects are studied, the typology of rhyming in Chinese dialects can be analyzed, creating a useful reference for the study of Chinese historical phonology.